This program is a combination of seven projects. The first one proposes to investigate the mechanism of in vivo and in vitro modifications of radiation response in a mouse chondrosarcoma solid tumor utilizing chemical and immunologic agents. A second project aims for the isolation and identification of insecticidal natural products for the control of Aedes aegypti. The third project deals with the radiation chemistry of biologically important compounds such as antitumor purines and folic acid. The fourth project studies the inhibitory activity of the alkaloids nitidine, fagaronine and related compounds. The use of these compounds in the radiotherapeutic treatment of cancerous tissues will be investigated. Other project involves the determination of atmospheric particulate and its relation to public health. Chemical and biological analysis of this airborne paticulate will be carried out. A sixth project involves the isolation and identification of thermophilic and mesophilic actinomycetes and fungi from clinical and environmental samples. The last project studies the effect of temperature on selected permeases (sulfate, methionine, gucose) of specific thermophilic (Penicillium duponti) and mesophilic Penicillium chrysogenum) fungi.